*{
    margin:0;
    padding:0;
}
body{
    background:lightpink;
}
#canvas{
    width:800px;
    height:800px;
    position:absolute;
    left:50%;
    top:50%;
    transform:translate(-50%,-50%);
    border:1px solid white;
    box-shadow:0 0 2vw white,inset 0 0 1vw white;